The present invention relates to electrical connectors and electrical junction boxes, and in particular to an improved electrical connector for lighting circuits etc.
Electrical junction boxes are commonly used in both domestic and commercial environments. Junction boxes typically provide a secure and relatively maintenance-free method of connecting fixed wiring in indoor applications, whether that be under a floor, in a ceiling void, in an attic or in any place where cables need to be joined together, for example, to extend and/or re-wire an existing circuit etc.
A common type of junction box consists of an array of four separate screw terminals, all housed within an insulated body having a removable lid to facilitate access for wiring up the box. Usually, each of the four terminals will have two or more cable cores connected to it, so that different wiring configurations of the incoming cables can be achieved. One example of a use of a junction box is to connect a supply to a switch and a light source (such as domestic lighting), so that the switch can operate the light. In many cases, an additional power cable may also be wired into the junction box to enable onward supply to another lighting circuit or spur, so that further lights may be controlled.
A further use of a junction box may alternatively be to simply serve as a means for connecting up a number of cables to a common connector.
Although conventional junction boxes are useful, they do suffer from several notable disadvantages. For example, junction boxes typically require a considerable length of time in order to be safely wired up. Moreover, given the arrangement of terminals and cores, specialist electrical knowledge is normally needed to ensure that the wiring is done correctly and that the preparation of the cable (e.g. the stripped length of the cores etc.) is carried out properly to enable the cables to reach each of the required terminals without stressing the core and while avoiding any possibility of short circuits. Even when the cable cores have been suitably prepared, it may still be quite difficult for an electrician to simultaneously position and retain up to four cable cores under a particular terminal screw until such time that he is able to tighten the screw. Such a task can be further exacerbated if access to the junction box is limited or otherwise inconvenient due to its location. Additional difficulties may ensue where a twin and earth cable is being used, in that it is then necessary to separately sleeve or sheath the earth conductor to insulate the core from the other cores, while also identifying the core as an earth conductor.
Wiring regulations in some countries now consider junction boxes with screw terminals to require maintenance, and consequently only permit their use where there is reasonable access for servicing. Since junction boxes, particularly in domestic settings, are often located within ceiling voids or between flooring etc., access may be problematic or indeed impossible, for example, if the ceiling is plastered or the overlying floor has a fixed carpet or wooden laminate flooring etc. In such situations, it may be possible to install special inspection plates, but this is rarely desirable given the expense and aesthetically displeasing end result.
It may be possible in some arrangements to gain access to a junction box via a hole or aperture in the ceiling where a recessed light fitting (e.g. a spotlight) is installed. However, more often than not, common junction boxes (as those described above) are invariably too large and cumbersome to be removed through the hole of a typical recessed light fitting, since not only may the box itself be bulky but it will normally have multiple cables radiating from the box. It is expected that as new lighting technology develops, the holes for recessed light fittings are likely to become smaller and smaller, and consequently access to junction boxes via this method will prove to be even more difficult with time.
Finally, some countries have also further updated their wiring regulations to require that cables which are not continuously supported, must have their outer sheaths secured where they are terminated. Therefore, in the case of a common junction box (which does not have cable or sheath grips), it is necessary to support the cables by, for example, fixing them with cable clamps to the fabric of the building (e.g. a roof joist etc.) to avoid the unsupported cables from exerting undue force on the individually terminated conductors. In such scenarios, it is therefore impossible to access and remove the junction box, irrespective of its size, from the hole of a recessed light fitting etc.
In response to the problems posed by common junction boxes, the prior art has offered some limited solutions, which have typically involved streamlining the shape of the junction box and including cable or sheath grips. However, in each example it remains the case that a significant amount of wiring up of the cables is required, usually with specialist knowledge, which is both fiddly and time consuming. While cable or sheath grips just add an additional time penalty to the time required for wiring the junction box. Moreover, in most of the solutions provided by the art, the hole or aperture required for access is still reasonably large, which is problematic given the trend for ever smaller and smaller light fittings.
It is therefore an object of the present invention to mitigate or overcome the above drawbacks and problems in the art and to provide a quick, safe and maintenance-free electrical connector for connecting multiple cables together, while addressing the issue of accessibility.